1. Field of the Invention
This invention relates to automatic article vendors and, more particularly, to vendors for storing a plurality of articles, stacked in columns, and for individually dispensing the articles.
2. Description of the Prior Art
While there exists a variety of bending machines for storing and dispensing articles, a subgroup of these machines have been designed in an attempt to maximize storage capacity without decreasing accessibility to the articles for dispensing purposes. A configuration allowing maximum storage capacity can have, for example, the articles stacked and the stacks grouped together so that the articles are in close proximity to each other. However, in such a configuration, the article can not be stacked so closely so as to make inaccessible any or all of same.
Attempts have been made to obtain optimal storage capacity in vending machines by using barrel or carousel type storage units such as those disclosed in U.S. Pat. Nos. 3,807,788 and 767,121. These carousel storage units include a plurality of generally parallel, spaced shelves having a central hub and a general circular outer edge. The shelves are mounted on an elongate shaft extending through the hubs so that the shelves are perpendicular to the shaft. Each shelf is further sectioned into wedge-shaped portions by wall members extending outwardly from the elongate shaft and perpendicular to the shelf.
The disadvantage with this carousel design is that the shelves themselves occupy space that could otherwise be used to store articles. The article receiving compartments formed by the shelves and walls must be larger than the articles and the spacing between adjacent shelves must be greater than the height of the articles to facilitate article retrieval.
Other prior art devices such as those represented by U.S. Pat. Nos. 1,689,039; 811,756; and a Canadian device employ carousels that allow the article to be stored stacked one on the other in columns, the space consuming shelves being eliminated. In these prior art devices, access to the stacked articles is generally had by removing the articles, one at a time, from the bottom of the stack. In the case of U.S. Pat. No. 1,639,039, the columns of articles are moved along a circular path with the columns of articles in frictional contact with a supporting and stationary base. Preparatory to vending, the column of articles become engaged in a curved guideway recessed in the base and the bottom article in the column is individually sheared away from its column as the column of articles move along this circular path.
The disadvantages inherent in this type carousel are that additional energy must be expended to overcome the above-indicated frictional force, and further, articles so stacked tend to become fouled by the guideways. The Canadian device, however, supports a stack of articles on a pivotable support finger above a stationary base and delivers them one at a time to be dispensed through a trapdoor.
The prior art device disclosed in U.S. Pat. No. 811,756, while utilizing a base that revolves with the stacked article so as to eliminate the aforementioned frictional force, suffers an additional disadvantage also inherent in other prior art. This disadvantage is that the carousel basically can handle only one size of article and there are no provisions to store and individually feed articles of varying sizes.